Mine is a Mitec brand but most of them seem to come out of the same factory and they paint them up for different suppliers. My old one was a WSE or something like that and the plasma is a Riland.
Welding thin materials is always a challenge. Stainless and Steel is not to hard. I use thiorated (sp?) electrodes on steel these have a red painted end. Grind them to a tapered sharp point and have the wheel running in the same direction at the electrode i.e don't grind across it seems to stuff up the shape of the arc. You should also wear a dust mask when grinding them as they are mildly radioactive.
For aluminium use just straight tungsten (white painted end). Don't grind them, just run them straight out of the packet. They will round the end over nicely as you use them.
A few factors that improved the quality of my welds:
Get a good quality automatic welding helmet that lets you adjust the shade as well as the delay switch off delay and sensitivity. When you are tig welding you are generally not making such a bright arc as with mig so the cheap helmets can flicker on and off. adjusting to the lightest comfortable shade will let you better see and control the weld pool. Mine cost about $300 but it was well worth it.
Pick up a gas lense for your torch. They aren't that expensive. I found it gave much better results as the argon was shielding weld better.
TIG Torch Article
Cheers